Apparatus and method for controlling fault in lighting network

ABSTRACT

Disclosed herein is an apparatus and method for controlling a fault in a lighting network. The apparatus includes power selection units respectively provided in a plurality of lighting units connected to one another over a network, each power selection unit being configured to compare a reference voltage with an output voltage sensed from power supply signals input from power supply units respectively provided in a lighting unit, located ahead of a faulty lighting unit, and the faulty lighting unit if a fault occurs in the lighting unit, and to select supply power to be supplied to the faulty lighting unit. Lighting control units control driving of the faulty lighting unit using the selected supply power.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No.10-2012-0072347, filed on Jul. 3, 2012, which is hereby incorporated byreference in its entirety into this application.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates generally to an apparatus and method forcontrolling a fault in a lighting network and, more particularly, to anapparatus and method for controlling a fault in a lighting network,which use a daisy-chain network topology based on a Recommended Standard485 (RS485) communication scheme.

2. Description of the Related Art

Recently, the importance of the Light Emitting Diode (LED) lightingindustry has gradually increased. In the past, most operations forlighting were implemented merely by turning on and off a single lightinglamp using a single switch. However, recently, such a lighting schemehas developed into a centralized scheme in which a central control unitcontrols a plurality of lighting devices over a network.

In order to implement such a lighting network, various types oftopological structures can be used. First, RS485 communication enables atopology to be configured in a bus manner and enables a plurality ofdevices to be simultaneously connected to the bus, so that one-to-manycommunication or many-to-many communication can be realized. Such astructure is widely used in lighting networks at the present time.

In detail, bus structures that can be implemented using an RS485communication scheme include a tree bus structure, a star structure, ora daisy-chain bus structure.

First, the tree bus structure is characterized in that the current ofsignals can be weakened while data transmitted from a lighting controldevice is reaching a lighting device in a final stage, so that aneffective range of 1.2 km of the RS485 communication scheme may not beguaranteed. Therefore, such a tree bus structure is useful for thecontrol of a small number of lighting devices, but causes a problem inconnecting and operating a plurality of lighting devices in conjunctionwith one another.

Next, the daisy-chain bus structure can be configured such that datatransmitted from a lighting control apparatus disclosed in Korean PatentNo. 100870733 (Date of registration: Nov. 20, 2008) entitled “Remotelighting control apparatus and method,” is connected to a neighboringlighting device, and that lighting device is connected to itsneighboring lighting device, so that the individual lighting devices canbe connected in series. Such a daisy-chain bus structure is advantageousin that the loss of current is low and the influence of noise is less,and in that the length of a cable can be reduced because the individuallighting devices are connected in series. However, such a daisy-chainbus structure is problematic in that when a fault occurs in a singlelighting device, none of the lighting devices may be normally operated.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made keeping in mind theabove problems occurring in the prior art, and an object of the presentinvention is to provide an apparatus and method for controlling a faultin a lighting network, in which neighboring lighting units can normallytransmit lighting control data without being influenced by a faultylighting unit even if a fault occurs in one of a plurality of lightingunits based on the lighting network.

In accordance with an aspect of the present invention to accomplish theabove object, there is provided an apparatus for controlling a fault ina lighting network, including power selection units respectivelyprovided in a plurality of lighting units connected to one another overa network, each power selection unit being configured to compare areference voltage with an output voltage sensed from power supplysignals input from power supply units respectively provided in alighting unit located ahead of a faulty lighting unit and in the faultylighting unit if a fault occurs in the lighting unit, and to selectsupply power to be supplied to the faulty lighting unit; and lightingcontrol units for controlling driving of the faulty lighting unit usingthe selected supply power.

Preferably, each of the lighting control units may include a firsttransceiver unit for receiving a differential signal required to controlthe plurality of lighting units from a lighting central management unitand converting the differential signal into a digital signal; a lightingcontrol logic unit for receiving the differential signal converted intothe digital signal, and then generating a lighting control signal; asecond transceiver unit for re-converting the lighting control signalgenerated from the digital signal into a differential signal, andtransmitting the differential signal to a lighting unit located behindthe faulty lighting unit; and a lighting drive unit for receiving thelighting control signal, and then driving the corresponding lightingunit.

Preferably, the lighting control logic unit may include a data detectionblock for buffering the differential signal converted into the digitalsignal and detecting lighting control data; a data generation block forgenerating only usage data to be used for the faulty lighting unit fromthe detected lighting control data; a lighting control signal generationblock for generating a lighting control signal required for lightingcontrol from the usage data; a data storage block for storing the usagedata; and a timing generation block for controlling generation andsynchronization of a clock signal used for the above blocks.

Preferably, the power selection unit may be configured to, if an outputvoltage input from a lighting control unit provided in a lighting unitlocated ahead of the faulty lighting unit or an output voltage inputfrom the power supply unit is less than a preset reference voltage,select power input from the lighting unit located ahead of the faultylighting unit as supply power.

Preferably, the power selection unit may be configured to, if an outputvoltage input from a lighting control unit provided in a lighting unitlocated ahead of the faulty lighting unit or an output voltage inputfrom the power supply unit is greater than a preset reference voltage,re-compare the output voltage input from the lighting control unitprovided in the lighting unit located ahead of the faulty lighting unitwith the reference voltage.

Preferably, upon performing the re-comparison, if the reference voltageis greater than the output voltage input from the lighting control unitprovided in the lighting unit located ahead of the faulty lighting unit,the power input from the lighting unit located ahead of the faultylighting unit may be selected as the supply power.

Preferably, upon performing the re-comparison, if the reference voltageis less than the output voltage input from the lighting control unitprovided in the lighting unit located ahead of the faulty lighting unit,power input from a charging unit for providing a charging voltage to thepower supply unit may be selected as the supply power.

In accordance with another aspect of the present invention to accomplishthe above object, there is provided a method of controlling a fault in alighting network, including determining, by power selection unitsrespectively provided in a plurality of lighting units connected to oneanother over a network, whether a fault has occurred in the lightingunits; if it is determined that the fault has occurred, receiving powersupply signals respectively input from power supply units provided in alighting unit located ahead of a faulty lighting unit and in the faultylighting unit; sensing an output voltage from the received power supplysignals and comparing the output voltage with a reference voltage;selecting supply power to be supplied to the faulty lighting unit basedon results of the comparison; and controlling, by a lighting controlunit, driving of the faulty lighting unit using the selected supplypower.

Preferably, the method may further include, after the sensing the outputvoltage from the received power supply signals and comparing the outputvoltage with the reference voltage, if an output voltage input from thelighting control unit provided in the lighting unit located ahead of thefaulty lighting unit or an output voltage input from the power supplyunit is greater than a preset reference voltage, re-comparing the outputvoltage input from the lighting control unit provided in the lightingunit located ahead of the faulty lighting unit with the referencevoltage.

Preferably, after the re-comparing the output voltage input from thelighting control unit provided in the lighting unit located ahead of thefaulty lighting unit with the reference voltage, if the referencevoltage is greater than the output voltage input from the lightingcontrol unit provided in the lighting unit located ahead of the faultylighting unit upon performing the re-comparison, the power input fromthe lighting unit located ahead of the faulty lighting unit may be usedas the supply power to be supplied to the faulty lighting unit at theselecting the supply power.

Preferably, after the re-comparing the output voltage input from thelighting control unit provided in the lighting unit located ahead of thefaulty lighting unit with the reference voltage, if the referencevoltage is less than the output voltage input from the lighting controlunit provided in the lighting unit located ahead of the faulty lightingunit upon performing the re-comparison, power input from a charging unitfor supplying a charging voltage to the power supply unit may be used asthe supply power to be supplied to the faulty lighting unit at theselecting the supply power.

Preferably, the selecting the supply power to be supplied to the faultylighting unit based on the results of comparison may be configured to,if as the results of the comparison, an output voltage input from thelighting control unit provided in the lighting unit located ahead of thefaulty lighting unit or an output voltage input from the power supplyunit is less than a preset reference voltage, use power output from thelighting unit located ahead of the faulty lighting unit as the supplypower to be supplied to the faulty lighting unit.

The apparatus and method for controlling a fault in a lighting networkaccording to the present invention, having the above configuration, areadvantageous in that lighting control data is normally transmitted usinga power supply method so that, even if a fault occurs in one of aplurality of lighting units based on a lighting network, lighting unitsneighboring a faulty lighting unit are not influenced by the faultylighting unit, thus actively controlling lighting network communication.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will be more clearly understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a diagram showing the configuration of an apparatus forcontrolling a fault in a lighting network according to an embodiment ofthe present invention;

FIG. 2 is a block diagram showing the detailed configuration of alighting control unit employed in the apparatus for controlling a faultin a lighting network according to an embodiment of the presentinvention;

FIG. 3 is a diagram showing the flow of differential signals and powersupply signals in the apparatus for controlling a fault in a lightingnetwork according to an embodiment of the present invention;

FIG. 4 is a block diagram showing the detailed configuration of alighting control logic unit employed in the lighting control unitaccording to an embodiment of the present invention; and

FIG. 5 is a flowchart showing a method of controlling a fault in alighting network according to an embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described indetail below with reference to the accompanying drawings to such anextent that those skilled in the art can easily implement the technicalspirit of the present invention. Reference now should be made to thedrawings, in which the same reference numerals are used throughout thedifferent drawings to designate the same or similar components. In thefollowing description, redundant descriptions and detailed descriptionsof known elements or functions that may unnecessarily make the gist ofthe present invention obscure will be omitted.

Hereinafter, an apparatus and method for controlling a fault in alighting network according to embodiments of the present invention willbe described in detail with reference to the attached drawings.

FIG. 1 is a diagram showing the configuration of an apparatus forcontrolling a fault in a lighting network according to an embodiment ofthe present invention, FIG. 2 is a block diagram showing the detailedconfiguration of a lighting control unit employed in the apparatus forcontrolling a fault in a lighting network according to an embodiment ofthe present invention, FIG. 3 is a diagram showing the flow ofdifferential signals and power supply signals in the apparatus forcontrolling a fault in a lighting network according to an embodiment ofthe present invention, and FIG. 4 is a block diagram showing thedetailed configuration of a lighting control logic unit employed in thelighting control unit according to an embodiment of the presentinvention.

Referring to FIG. 1, an apparatus 100 for controlling a fault in alighting network according to the present invention may mainly includelighting control units 100 a to 100 b and a lighting central managementunit 200.

The lighting central management unit 200 outputs differential signalsrequired to control a plurality of lighting units connected over anetwork. That is, the lighting central management unit 200 transmits acontrol signal required to control the lighting units as a differentialsignal A₁-B₁ to the lighting control unit 100 a, and this differentialsignal is sequentially transferred to the lighting control unit 100 blocated at the end of the apparatus. Here, the differential signal isindicated by A₁-B₁, A₂-B₂, A₃-B₃, A_(n-1)-B_(n-1), and A_(n)-B_(n) inthe drawing.

The lighting control units 100 a to 100 b are respectively provided inthe plurality of lighting units and are configured to control thedriving of a faulty lighting unit based on a differential signal and anexternally input power supply signal when a fault occurs in thecorresponding lighting unit. The power supply signal is V_(n), which isindicated by V₁, V₂, V₃, V_(n-1), V_(n), and GND. Here, GND is a signalconnected in common to the lighting central management unit 200 and allof the lighting control units 100 a to 100 b.

For this, as shown in FIGS. 2 and 3, each of the lighting control units100 a to 100 b includes a first transceiver unit 110, a lighting controllogic unit 120, a second transceiver unit 130, a lighting drive unit140, a power selection unit 150, and a power supply unit 160.

The first transceiver unit 110 converts an input differential signalinto a digital signal. In this case, the first transceiver unit 110receives a differential signal A_(n-1) and B_(n-1) from the lightingcentral management unit 200, converts the differential signal into adigital signal, and receives power supply signals V_(n) and GND from theoutside of the lighting control unit.

The lighting control logic unit 120 receives the differential signalconverted into the digital signal, and then generates a lighting controlsignal. For this, as shown in FIG. 4, the lighting control logic unit120 includes a data detection block 121 for buffering the differentialsignal converted into the digital signal and detecting lighting controldata, a data generation block 122 for generating only usage data that isused for a faulty lighting unit from the detected lighting control data,a lighting control signal generation block 124 for generating a lightingcontrol signal required for lighting control from the usage data, a datastorage block 123 for storing the usage data, and a timing generationblock 125 for controlling the generation and synchronization of a clocksignal used for the above components.

The second transceiver unit 130 reconverts the lighting control signal,generated from the digital signal, into a differential signal, andtransmits the differential signal to a lighting unit located behind afaulty lighting unit.

The lighting drive unit 140 receives the lighting control signal anddrives the corresponding lighting unit.

The power selection unit 150 senses an output voltage via a powersensing unit 151 from power supply signals respectively received fromthe lighting control unit 100 a provided in a lighting unit locatedahead of a faulty lighting unit and the power supply unit 160 providedin the faulty lighting unit, compares the sensed output voltage with areference voltage, and selects whether to use power input from thelighting central management unit 200 or power input from the lightingunit located ahead of the faulty lighting unit as power to be suppliedto the faulty lighting unit.

That is, if an output voltage V_(n-1) input from the lighting controlunit 100 a to 100 b provided in a lighting unit located ahead of thefaulty lighting unit or an output voltage V_((n-1)^2) input from thepower supply unit 160 is less than a preset reference voltage, the powerselection unit 150 selects and uses the voltage, output from thelighting control unit 100 a to 100 b provided in the lighting unitlocated ahead of the faulty lighting unit, as the power to be suppliedto the faulty lighting unit.

In contrast, if the output voltage input from the lighting control unit100 a to 100 b provided in the lighting unit located ahead of the faultylighting unit or the output voltage input from the power supply unit 160is greater than the preset reference voltage, the power selection unit150 re-compares the output voltage input from the lighting control unit100 a to 100 b provided in the lighting unit located ahead of the faultylighting unit with the reference voltage. In this case, if the presetreference voltage is greater than the output voltage input from thelighting control unit 100 a to 100 b provided in the lighting unitlocated ahead of the faulty lighting unit, the voltage output from thelighting control unit 100 a to 100 b provided in the lighting unitlocated ahead of the faulty lighting unit is selected as the power to besupplied to the faulty lighting unit. If the preset reference voltage isless than the output voltage input from the lighting control unit 100 ato 100 b provided in the lighting unit located ahead of the faultylighting unit, a voltage of V_((n-1)^2) output from a charging unit 161is selected and used as the power to be supplied to the faulty lightingunit.

The power supply unit 160 is a main power source for supplyingsufficient power required to drive the corresponding lighting unit, andis provided with the charging unit 161 as an emergency power source. Inthis case, the charging unit 161 provides a charging voltage to thepower supply unit 160 in preparation for the case where a fault occursin two or more lighting control units 100 a to 100 b.

FIG. 5 is a flowchart showing a method of controlling a fault in alighting network according to an embodiment of the present invention.

Referring to FIG. 5, in the method of controlling a fault in a lightingnetwork according to the present invention, each of power selectionunits respectively provided in a plurality of lighting units connectedto one another over a network determines whether a fault has occurred inthe corresponding lighting unit at step S100.

If it is determined that a fault has occurred, power supply signalsrespectively input from a power supply unit provided in a lighting unitlocated ahead of a faulty lighting unit, and a power supply unitprovided in the faulty lighting unit are received at step S200.

Next, an output voltage is sensed from the input power supply signalsand is then compared with a reference voltage at step S300.

Next, based on the results of the comparison, supply power to besupplied to the faulty lighting unit is selected at step S400. Based onthe results of the comparison, if the output voltage input from thelighting control unit 100 a to 100 b provided in the lighting unitlocated ahead of the faulty lighting unit or the output voltage inputfrom the power supply unit 160 is less than the preset referencevoltage, the voltage output from the lighting control unit 100 a to 100b provided in the lighting unit located ahead of the faulty lightingunit is selected and used as the power to be supplied to the faultylighting unit. In contrast, at the comparison step, if the outputvoltage input from the lighting control unit 100 a to 100 b provided inthe lighting unit located ahead of the faulty lighting unit or theoutput voltage input from the power supply unit 160 is greater than thepreset reference voltage, the output voltage input from the lightingcontrol unit 100 a to 100 b provided in the lighting unit located aheadof the faulty lighting unit is re-compared with the reference voltage.In this case, upon performing the re-comparison, if the referencevoltage is greater than the output voltage input from the lightingcontrol unit 100 a to 100 b provided in the lighting unit located aheadof the faulty lighting unit, the voltage output from the lightingcontrol unit 100 a to 100 b provided in the lighting unit located aheadof the faulty lighting unit is selected and used as the power to besupplied to the faulty lighting unit at the power selection step.Further, upon performing the re-comparison, if the reference voltage isless than the output voltage input from the lighting control unit 100 ato 100 b provided in the lighting unit located ahead of the faultylighting unit, the voltage output from the charging unit 161 thatprovides the charging voltage to the power supply unit is selected andused as the power to be supplied to the faulty lighting unit at thepower selection step.

Next, the lighting control unit controls the driving of the faultylighting unit using the selected supply power at step S500.

In this way, the present invention normally transmits lighting controldata using a power supply method so that, even if a fault occurs in oneof a plurality of lighting units based on a lighting network, lightingunits neighboring a faulty lighting unit are not influenced by thefaulty lighting unit, thus actively controlling lighting networkcommunication.

Although the preferred embodiments of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

What is claimed is:
 1. An apparatus for controlling a fault in alighting network, comprising: power selection units respectivelyprovided in a plurality of lighting units connected to one another overa network, each power selection unit being configured to compare areference voltage with an output voltage sensed from power supplysignals input from power supply units respectively provided in alighting unit located ahead of a faulty lighting unit and in the faultylighting unit if a fault occurs in the lighting unit, and to selectsupply power to be supplied to the faulty lighting unit; and lightingcontrol units for controlling driving of the faulty lighting unit usingthe selected supply power.
 2. The apparatus of claim 1, wherein each ofthe lighting control units comprises: a first transceiver unit forreceiving a differential signal required to control the plurality oflighting units from a lighting central management unit and convertingthe differential signal into a digital signal; a lighting control logicunit for receiving the differential signal converted into the digitalsignal, and then generating a lighting control signal; a secondtransceiver unit for re-converting the lighting control signal generatedfrom the digital signal into a differential signal, and transmitting thedifferential signal to a lighting unit located behind the faultylighting unit; and a lighting drive unit for receiving the lightingcontrol signal, and then driving the corresponding lighting unit.
 3. Theapparatus of claim 2, wherein the lighting control logic unit comprises:a data detection block for buffering the differential signal convertedinto the digital signal and detecting lighting control data; a datageneration block for generating only usage data to be used for thefaulty lighting unit from the detected lighting control data; a lightingcontrol signal generation block for generating a lighting control signalrequired for lighting control from the usage data; a data storage blockfor storing the usage data; and a timing generation block forcontrolling generation and synchronization of a clock signal used forthe above blocks.
 4. The apparatus of claim 1, wherein the powerselection unit is configured to, if an output voltage input from alighting control unit provided in a lighting unit located ahead of thefaulty lighting unit or an output voltage input from the power supplyunit is less than a preset reference voltage, select power input fromthe lighting unit located ahead of the faulty lighting unit as supplypower.
 5. The apparatus of claim 1, wherein the power selection unit isconfigured to, if an output voltage input from a lighting control unitprovided in a lighting unit located ahead of the faulty lighting unit oran output voltage input from the power supply unit is greater than apreset reference voltage, re-compare the output voltage input from thelighting control unit provided in the lighting unit located ahead of thefaulty lighting unit with the reference voltage.
 6. The apparatus ofclaim 5, wherein upon performing the re-comparison, if the referencevoltage is greater than the output voltage input from the lightingcontrol unit provided in the lighting unit located ahead of the faultylighting unit, the power input from the lighting unit located ahead ofthe faulty lighting unit is selected as the supply power.
 7. Theapparatus of claim 5, wherein upon performing the re-comparison, if thereference voltage is less than the output voltage input from thelighting control unit provided in the lighting unit located ahead of thefaulty lighting unit, power input from a charging unit for providing acharging voltage to the power supply unit is selected as the supplypower.
 8. A method of controlling a fault in a lighting network,comprising: determining, by power selection units respectively providedin a plurality of lighting units connected to one another over anetwork, whether a fault has occurred in the lighting units; if it isdetermined that the fault has occurred, receiving power supply signalsrespectively input from power supply units provided in a lighting unitlocated ahead of a faulty lighting unit and in the faulty lighting unit;sensing an output voltage from the received power supply signals andcomparing the output voltage with a reference voltage; selecting supplypower to be supplied to the faulty lighting unit based on results of thecomparison; and controlling, by a lighting control unit, driving of thefaulty lighting unit using the selected supply power.
 9. The method ofclaim 8, further comprising, after the sensing the output voltage fromthe received power supply signals and comparing the output voltage withthe reference voltage, if an output voltage input from the lightingcontrol unit provided in the lighting unit located ahead of the faultylighting unit or an output voltage input from the power supply unit isgreater than a preset reference voltage, re-comparing the output voltageinput from the lighting control unit provided in the lighting unitlocated ahead of the faulty lighting unit with the reference voltage.10. The method of claim 9, wherein after the re-comparing the outputvoltage input from the lighting control unit provided in the lightingunit located ahead of the faulty lighting unit with the referencevoltage, if the reference voltage is greater than the output voltageinput from the lighting control unit provided in the lighting unitlocated ahead of the faulty lighting unit upon performing there-comparison, the power input from the lighting unit located ahead ofthe faulty lighting unit is used as the supply power to be supplied tothe faulty lighting unit at the selecting the supply power.
 11. Themethod of claim 9, wherein after the re-comparing the output voltageinput from the lighting control unit provided in the lighting unitlocated ahead of the faulty lighting unit with the reference voltage, ifthe reference voltage is less than the output voltage input from thelighting control unit provided in the lighting unit located ahead of thefaulty lighting unit upon performing the re-comparison, power input froma charging unit for supplying a charging voltage to the power supplyunit is used as the supply power to be supplied to the faulty lightingunit at the selecting the supply power.
 12. The method of claim 8,wherein the selecting the supply power to be supplied to the faultylighting unit based on the results of comparison is configured to, if asthe results of the comparison, an output voltage input from the lightingcontrol unit provided in the lighting unit located ahead of the faultylighting unit or an output voltage input from the power supply unit isless than a preset reference voltage, use power output from the lightingunit located ahead of the faulty lighting unit as the supply power to besupplied to the faulty lighting unit.